Copper in foods

About 50% of copper in food is absorbed, usually under equitibrium conditions, and stored in the tiver and muscles. Excretion is mainly via the bile, and only a few percent of the absorbed amount is found in urine. The excretion of copper from the human body is influenced by molybdenum. A low molybdenum concentration in the diet causes a low excretion of copper, and a high intake results in a considerable increase in copper excretion (68). This copper—molybdenum relationship appears to correlate with copper deficiency symptoms in cattle. It has been suggested that, at the pH of the intestine, copper and molybdate ions react to form biologically unavailable copper molybdate (69). 

Anemia can be induced in animals on a low copper diet, such as milk, and appears 10 be due to an impaired ability of the body to absorb iron. This anemia, however, is rare, because of the widespread occurence of copper in foods. In locations, such as Australia and lire Netherlands, diseases of cattle and sheep, involving diarrhea, anemia and nervous disorders, can be traced either to a lack of copper in the diet, or to excessive amounts of molybdenum, which inhibits the storage of copper in the liver. 

The average North American diet contains 3-5 mg copper per day. Because of the ubiquitous presence of copper in food constituents and even in drinking water, it is difficult to devise a balanced diet composed of natural foods that contains less than 1 mg copper per day. The daily minimal requirement of copper for the adult man is stated to be 2 mg per day (C5). Infants require 0.05 mg/kg body weight per day (Nl). These figures are only approximate and most probably far too high, since copper deficiency has not been produced with much lower intakes of copper (W3). 

V.A. Lemos, A.A. Jesus, E.M. Gama, G.T. David, R.T. Yamaki, On-line solid phase extraction and determination of copper in food samples using polyurethane foam loaded with Me-BTANC, Anal. Lett. 38 (2005) 683. 

In Switzerland, the regulations prescribe the following maximal concentrations of copper in food (mg kg , resp. mg Cu) pectins, 400 fruit juices, grape juice, vinegar, and alcoholic liquors, 5-30, milk,... 

Abbasi, S., Khani, H. and Tabaraki, R. (2010) Determination of ultra trace levels of copper in food samples by a highly sensitive adsorptive stripping voltammetric method. Food Chem., 123, 507-512. 

Chaiyo, S., Chailapakul, O., Sakai, T., Teshima, N., and Siangproh, W. (2013) Highly sensitive determination of trace copper in food by adsorptive stripping voltammetry in the presence of 1,10-phenanthroline. Talanta, 108, 1-6. 

Copper is a one of important trace element required for many biochemical and physiological functions, but excess quantity of this metal in water and food may have undesirable consequences. In accordance with Russian sanitary standai d, general concentration of copper in drinking, fresh, domestic waters and in treated effluent hasn t to be more than 1 mg/1. 

There have been numerous reports of possible allergic reactions to mercury and mercury salts and to the mercury, silver and copper in dental amalgam as well as to amalgam corrosion products Studies of the release of mercury by amalgams into distilled water, saline and artificial saliva tend to be conflicting and contradictory but, overall, the data indicate that mercury release drops with time due to film formation and is less than the acceptable daily intake for mercury in food . Further, while metallic mercury can sensitise, sensitisation of patients to mercury by dental amalgam appears to be a rare occurrence. Nevertheless, there is a growing trend to develop polymer-based posterior restorative materials in order to eliminate the use of mercury in dentistry. 

In certain direct steam-contact process applications (such as in food and beverage processing or pharmaceutical preparations) the use of amine-based products in steam and condensate systems is subject to legal restrictions. Also, the use of ammonia or amines may be dependent on the materials of construction employed or technical limitations (such as the risk of copper alloy corrosion). 

Wieser, W. 1979. The flow of copper through a terrestrial food web. Pages 325-355 in J.O. Nriagu (ed.). Copper in the Environment. Part 1 Ecological Cycling. John Wiley, NY. 

Wood, E.C. and A.N. Worden. 1973. The influence of dietary copper concentration on hepatic copper in the duckling and the chick. Jour. Sci. Food Agricul. 24 167-174. 

Copper liver burden reduced to 201 mg/kg DW vs. 346 in controls copper in plasma elevated to 1100 pg/L vs. 690 in controls. No effect on growth, or food and water consumption (9) Normal milk Mo level of 0.06 mg/L (5)... 

Cadmium occurs naturally as sulfide co-deposited with zinc, copper, and lead sulfides. It is produced as a by-product in above-mentioned metal processing. Similar to lead and mercury, this heavy metal has no known biological functions in living organisms, and accordingly its accumulation in food and water leads to undesirable consequences to biota. Cadmium toxicology is related to dangerous influence to CNS and excretion systems, firstly, on kidney. 

Low levels of resistance have been reported for some populations of Indian meal moth, almond moth, and red flour beetle populations in stored peanuts in the southeastern United States (Zettler et al., 1989), but no assessments are available for phosphine resistance in insect populations in mills, warehouses, processing plants, and other structural facilities. Phosphine can be corrosive to metals, particularly copper, electrical wiring, and electronic equipment (Bond et al., 1984), which limits its application in food processing facilities and warehouses. A new formulation of phosphine, in which phosphine gas is combined with carbon dioxide and released from a cylinder, alleviates some but not all of the corrosive effects of phosphine and is labeled for use as a structural treatment. 

The appreciation of color and the use of colorants dates back to antiquity. The art of making colored candy is shown in paintings in Egyptian tombs as far back as 1500 bc. Pliny the Elder described the use of artificial colorants in wine in 1500 bc. Spices and condiments were colored at least 500 years ago. The use of colorants in cosmetics is better documented than colorants in foods. Archaeologists have pointed out that Egyptian women used green copper ores as eye shadow as early as 5000 bc. Henna was used to redden hair and feet, carmine to redden lips, faces were colored yellow with saffron and kohl, an arsenic compound, was used to darken eyebrows. More recently, in Britain, in the twelfth century, sugar was colored red with kermes and madder and purple with Tyrian purple. 

Oxidants are present in the environment and in foods. Nitrogen oxides are oxidants present in cigarette smoke and urban smog. Other oxidants include the copper and iron salts in meat and some plants. Inhaling and ingesting oxidants such as these can increase the level of oxidants in our bodies. 

Toxicological studies on direct food additives have revealed toxic and harmful actions. Food dyes and preservatives have been used since ancient Roman times to improve the color of wine or to disinfect wine containers. The development of chemistry led to many unwise experiments, such as the dying of food with copper, chrome, lead, mercury, arsenic, and cadmium salts. In the U.S. in 1906, over 300 food dyes were officially tested, of which only seven passed and were allowed to be used in food. Only two of them - erythrosine and idigotine - are permitted now. The lists of preservatives are also constantly modified in different countries. Quite recently, formic acid, which is used to preserve semi-products, was banned in Poland due to its deleterious effects. 

Copper is usually present in food at levels of 1 to 2 pg per g, the higher levels are found in animal livers. The highest levels of copper are present in shellfish, this is because copper is a component of their blood pigment, haemocyanin. 

Metals frequently occurring in the state s waste streams include cadmium, chromium, lead, arsenic, zinc, copper, barium, nickel, antimony, beryllium, mercury, vanadium, cobalt, silver, and selenium. These metals are toxic to humans and other organisms, are persistent in the environment, and can bioaccumulate in food chains. They are typically used by businesses in many industrial categories, as shown in Table 2.1-1. 

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